1.10/7x(200/13-20/11)x0.7x143/5 2.(204+584x1991/1992x584-380)-5/89 3.139x137/138+137x1/138
4.已知S=（1/3+1/5+1/7+1/11+1/13)X5005
5.199又1/9X1/8+599又1/7X1又1/6-201又1/9X9/10-601又1/7X7/8